1. Field of the Invention
The present invention relates to a head restraint assembly including a headrest supported on movable curved tubes which are operative to move the headrest upward and forward in vehicle when actuated in response to a vehicle impact.
2. Background Art
Head restraints used in vehicle seats, manually or automatically adjustable, are well known. The simplest of these devices are headrests which allow the occupant to manually adjust the headrest height to properly support his or her head. The manual adjustment is accomplished either through physically moving the headrest to the desired position, or by means of a motorized system which allows the occupant to electrically control movement of the headrest. The latter system provides the advantage of allowing the occupant to remain seated while the headrest is being adjusted, thereby helping to ensure that the proper headrest height is obtained.
More sophisticated devices include headrests that are connected to sensing devices which are part of an automated adjustment system. In these automated systems, sensors are located in one or more locations throughout the vehicle. The sensors typically detect the presence of an occupant as well as the seated height of the occupant; this information is then sent to a system controller. The controller in turn actuates a drive mechanism which causes the headrest to move vertically, and in some cases horizontally, to the proper position for supporting the occupant""s head.
One such device is disclosed in U.S. Pat. No. 6,088,640 issued to Breed on Jul. 11, 2000. Breed teaches a device that includes sensors for detecting the location of an occupant""s head and a mechanism for adjusting the headrest either vertically or horizontally as needed. This adjustment can occur continuously, or it can take place just prior to vehicle impact. To accomplish the latter, the system includes a sensor that emits signals from the rear of the vehicle to detect approaching objects. When the sensor signals a controller that a rear impact is about to occur, the controller adjusts the position of the headrest to provide support for the occupant during the anticipated impact. The headrest is adjusted through a series of lead screws that are turned by motors connected to the controller. The disadvantage of this device is that it requires the object sensor to anticipate a future impact so that the motors have time to adjust the headrest prior to the actual impact occurring.
Accordingly, it is desirable to provide a head restraint system for a vehicle that overcomes the shortcomings of prior art systems, by including a headrest that quickly deploys upward and toward the occupant upon vehicle impact, thereby providing support for the occupant""s head.
One aspect of the present invention provides a head restraint system for use in a vehicle seat that includes a headrest that quickly deploys upward and toward the occupant upon vehicle impact so as to provide support for the occupant""s head.
Accordingly, a vehicle seat and headrest assembly is provided that comprises a seat back and a headrest that is movably supported with respect to the seat back on a pair of curved guide tubes. The guide tubes are movable along guide elements, and the headrest is movable between a retracted position closely adjacent to the seat back, and an extended position extending away from the seat back and forwardly toward the head of a seated occupant. The headrest has a deployment mechanism for deploying the headrest from the retracted position to the extended position. The headrest also includes a locking device for locking the headrest in a desired vertical position and for disengaging it in the event of a vehicle impact. The disengagement of the locking device allows rapid movement of the headrest to the extended position.
In another aspect of the invention, a vehicle seat and headrest assembly is provided that comprises a seat back and a headrest capable of moving from a retracted position closely adjacent to the seat back, to a deployed position extending away from the seat back and forwardly toward the head of a seated occupant. The headrest is connected to first and second support tubes, which are connected to each other by a brace. The tubes support the headrest and move it between the retracted position and the deployed position. A plurality of guide elements support the tubes and pilot their movement while they move the headrest. A tension spring has one end connected to the brace, and the other end connected to a portion of the seat. The tension spring moves the support tubes to deploy the headrest. The assembly also includes a friction lock for selectively locking the first support tube for stopping movement of the headrest, and releasing the first support tube for facilitating movement of the headrest.
In a further aspect of the invention, a vehicle seat and headrest assembly is provided that comprises a seat back and a headrest capable of being deployed from a retracted position to a deployed position. The headrest is supported by a curved support member which moves the headrest upward and toward the occupant during deployment. A plurality of guide elements carry and pilot movement of the support member during deployment of the headrest. A spring actuated deployment mechanism operates to deploy the headrest. A friction lock has a closed position for locking the support member, thereby stopping deployment of the headrest. The friction lock also has an open position for releasing the support member, thereby facilitating deployment of the headrest. A solenoid is operatively connected to the friction lock for opening and closing it. A vehicle impact sensor signals the solenoid to open the friction lock when a vehicle impact is sensed, and an occupant sensor in the headrest signals the solenoid to close the friction lock when the occupant""s head contacts the headrest.
The above object and other objects, features, and advantages of the present invention are readily apparent from the following detailed description of the best modes for carrying out the invention when taken in connection with the accompanying drawings.